Method and apparatus for managing device context using an IP address in a communication system

ABSTRACT

The present invention relates to a system configuration and an apparatus for preventing the infringement of user privacy, and for collecting and analyzing information regardless of the service feature and type, while a system providing a context aware service collects and analyzes user information. The present invention discloses a method of configuring and using a context analyzer and a device profile database in order for the system providing the context aware service to collect and analyze information regardless of the service feature and type.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a continuation application of prior application Ser.No. 14/233,521, filed on Jan. 17, 2014, which will issue as U.S. Pat.No. 9,602,402 on Mar. 21, 2017, which is a U.S. National Stageapplication under 35 U.S.C. § 371 of an International application filedon Jul. 20, 2012 and assigned application number PCT/KR2012/005798, andclaimed the benefit under 35 U.S.C. § 119(a) of a Korean patentapplication filed on Jul. 20, 2011 in the Korean Intellectual PropertyOffice and assigned Serial number 10-2011-0071968, the entire disclosureof which is hereby incorporated by reference.

TECHNICAL FIELD

The present invention relates to a communication system and, inparticular, to a method and apparatus for collecting and managing useractivity and service usage context without invasion of user privacy.

BACKGROUND

The mobile communication system has been developed for the user tocommunicate on the move. With the rapid advance of technologies, themobile communication system has evolved to the level capable ofproviding high speed data communication service as well as voicetelephony service. Meanwhile, with the advent of high processingdevices, auxiliary memory devices, and display devices, the userterminal manufacturing technology has developed to the extent that thesmartphones capable of providing the user with high speed high qualitydata communication services on the move are popularized.

The development of high speed data communication service and widespreaduse of high performance smartphones spur the advent of novel userapplication services. Representative examples thereof include highquality multimedia video provision service (e.g. YouTube), SocialNetworking Service making it possible for users to share information andactivity (e.g. Facebook), and search service allowing users to findinformation anytime anywhere (e.g. google).

The next generation application service providers are developing ContextAware Service technologies competitively to provide the more enhanceduser experience. The context aware service is the technology ofpredicting the user's ultimate goal in the current situation based onthe service usage history of the user to improve the user convenience.Accordingly, in order to provide the user with the context awareservice, the service provider has to collect and retain the informationprevious user activity and service usage history information such asvisited webpages, used keywords, viewed videos, communicated persons,frequently visited areas. As the amount of collected user information(i.e. context) increases, the context aware service can be provided moreprecisely.

However, the context aware service is likely to invade personal privacyin the process that the server collects information. There is thereforea need of developing the method capable of providing enriched contextaware service without invading personal privacy.

SUMMARY

The present invention has been made in an effort to solve the aboveproblem and aims to provide a method and apparatus for collecting andmanaging user activity and service usage context without invading userprivacy in a communication service.

The system according to an embodiment of the present invention ischaracterized by introducing a context analyzer and a device profiledatabase (DB) capable of collecting and analyzing user informationindependently of service type without invasion of user privacy in theprocedure of collecting and analyzing user context for providing contextaware service.

The system for providing context aware service according to anembodiment of the present invention is characterized in that anapparatus for collecting and analyzing the context uses the IP addressin collecting and analyzing the user context without invasion of userprivacy.

The system for providing context aware service according to anembodiment of the present invention is characterized by a method capableof collecting and analyzing context continuously even when the IPaddress assigned to the user device is changed in the state of using theold IP address so as to collect and analyzing the user context withoutinvasion of the user privacy.

The system for providing context aware service according to anembodiment of the present invention is characterized by a method ofusing an alias of the device in order for the apparatus of collectingand analyzing the context to collect and analyze the user contextwithout invading user privacy.

In detail, a method for managing context in a communication systemaccording to the present invention includes detecting a packettransmitted between a device and a server, requesting a device profiledatabase for information on an IP address of the device by sending an IPrequest message, receiving an IP response message from the deviceprofile database, and updating the context according to the IP addressinformation in the IP response message.

Also, an apparatus for managing context in a communication systemaccording to the present invention includes an interface which isresponsible for wired or wireless communication with at least one node,a storage unit which stores context information associated with an IPaddress, and a control unit which detects a packet transmitted between adevice and a server, requests a device profile database for informationon an IP address of the device by sending an IP request message, andreceives an IP response message from the device profile database, andupdates the context according to the IP address information in the IPresponse message.

The present invention makes it possible for the user to provide thecontext aware service provider with user information anonymously and forthe context aware service provider to collect user information withoutinvading user privacy and provide the user with high value-addedservices. The service provider is capable of collecting and utilizingthe user context in various fields independently of service type.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram illustrating the network architecture for theconventional Internet service providers to provide users with contextaware services.

FIG. 2 is a diagram illustrating the network architecture for collectingand analyzing the context of the user interested in receiving varioustypes of service without invading user privacy.

FIG. 3 is a flow diagram illustrating the procedure for the contextanalyzer 302 to store and analyze, when the device 300 connects to thesystem first, context using the IP address of the device 300.

FIG. 4 is a flow diagram illustrating the procedure for the contextanalyzer 402 to detect, when the IP address assigned to the device 400is changed, the change and associate the IP address with the previouslystored and analyzed user information.

FIG. 5 is a flow diagram illustrating the procedure of collecting andanalyzing context based on the device alias.

FIG. 6 is a flowchart illustrating the context management procedure ofthe context analyzer according to an embodiment of the presentinvention.

FIG. 7 is a block diagram illustrating a configuration of the contextanalyzer according to an embodiment of the present invention.

DETAILED DESCRIPTION

Detailed description of well-known functions and structures incorporatedherein may be omitted to avoid obscuring the subject matter of thepresent invention. Exemplary embodiments of the present invention aredescribed with reference to the accompanying drawings in detail.

Although the embodiments of the present invention are directed to thebasic Internet system, it will be understood by those skilled in the artthat the present invention can be applied even to othercommunication/computer systems having the similar technical backgroundand system format, with a slight modification, without departing fromthe spirit and scope of the present invention.

In the following, the description on the present invention is directedto the system and apparatus capable of collecting and analyzinginformation independently of the characteristic and type of the servicewithout invading user privacy in the context aware service provisionsystem.

In the following description, the present invention proposes a methodfor the context aware service provision system to configure and use aContext Analyzer and a Device Profile DB for collecting and analyzingthe information independently of the characteristic and type of theservice. The present invention proposes a method for the context awareservice provision system to collect and analyze the context based on theIP address and alias of the device without invading the user privacy.

FIG. 1 is a diagram illustrating the network architecture for theconventional Internet service providers to provide users with contextaware services.

The user 100 may use a wired device 102 or a wireless device 106 forreceiving Internet service. The user 100 logs on the Internet serviceprovider server 112 and sends the server 112 the information requestingfor the Internet service.

For example, the user sends the service provider server 112 its currentlocation in order to use a location-based service. The service providerserver 112 sends the user appropriate information and service back basedon this information which is accumulated in the server 112 to improvethe quality of the context aware service other than one-off use.

However, the user context collection procedure of the current serviceproviders in the architecture of FIG. 1 has following drawbacks. First,since the user information is collected based on the log-on informationof the subscribed user 100 to the server 112, the user privacy may beinvaded. The user does not want the service provider to retain and usethe user activity information illegally. For example, the serviceprovider 112 may record the location of the user in real time and, ifsuch information is collected and used without consent of the user, thismay make the user 100 unpleasant.

Secondly, since the user context is stored per service provider, it isdifficult to collect the user context in various ranges. For example,the multimedia video service provider and the location-based serviceprovider may collect user contexts exclusively from each other.

The present invention has been conceived to solve the above problems andaims to provide a system structure capable of collecting userinformation without invasion of user privacy in the context awareservice provision system and without limit to specific serviceproviders.

FIG. 2 is a diagram illustrating the network architecture for collectingand analyzing the context of the user interested in receiving varioustypes of service without invading user privacy.

In the following description, the user context may include at least oneof purchase detail, user location, preference, click history, and SocialNetworking Service (SNS) information.

In order to solve the problem of the conventional technology depicted inFIG. 1, the network architecture proposed by the present inventionincludes a Context analyzer 200 and a device profile database 202. Thecontext analyzer 200 collects and analyzes user information inseparation from the server 102 providing the service. The device profileDB 202 stores the information for hiding the actual owner of thecollected user context.

In the network architecture proposed in an embodiment of the presentinvention as shown in FIG. 2, the context analyzer 200 positioned on thetransmission path collects and analyzes the information which the user100 transmits to the server 102. According to an embodiment of thepresent invention, it is advantageous to collect the information relatedto various types of services independently of the type and location ofthe service provider server 112. The context analyzer 200 may be ownedand used by the Internet service provider or mobile communicationnetwork operator.

The device profile DB 202 is the facility of recording the IP addressallocated to specific device without information on the user. That is,the device profile DB 202 stores the information on the IP address whichis currently used by a specific device and whether the device allocatedthe current IP has used other IP address in the past. The device profileDB 202 may be depicted in the form of a table as table 1.

TABLE 1 previous IP address current IP address 100.000.1011 121.516.6541111.181.2201 221.321.6542 132.213.8465 135.321.6557 — —

In another embodiment of the present invention, the device profile DB202 may store the alias of the device using a specific IP address.

In this way, the method according to an embodiment of the presentinvention traces only the IP address of the device to manage the contextinformation but not store or use the correlation between the IP addressof the device and the actual device or the user, thereby protecting theuser privacy from being invaded.

An embodiment of the present invention proposes a method of using theInternet Protocol (IP) address of the user device instead of theidentifier representing the user directly such as user name, andresident registration number, and the identifier representing the usersubscription information directly such as phone number and user IDwithout invading the user privacy. The present invention also proposes amethod of collecting and analyzing the context continuously even whenthe IP address allocated to the user device is changed.

FIG. 3 is a flow diagram illustrating the procedure for the contextanalyzer 302 to store and analyze, when the device 300 connects to thesystem first, context using the IP address of the device 300.

In the following description, it is assumed that the IP address of thedevice is allocated by a node such as gateway (not shown) and, if the IPaddress of the device is updated, the gateway notifies the deviceprofile DB of this. Accordingly, the device profile DB may update the IPaddress of the device whenever the IP address of the device is changed.

Returning to FIG. 3, the context analyzer 302 has no information on thedevice 300 at step 308 before the user connects. This is because theinitial connection of the device 300 to the system is assumed. Thedevice 300 is assigned an IP address for use of Internet at step 310 andsends the server the first packet ate step 312.

Then, the context analyzer 302 detects this at step 310 (Option 1) sendsthe device profile DB 306 an IP request message (Old IP Request) forinquiry on whether the corresponding device 300 has any IP address usedpreviously at step 318. If the device connects initially to receive theservice, it has no old IP address and thus the device profile DB 306sends the device 300 an IP response message (Old IP Response) to notifythat it is a new device having no old IP address at step 320. In thiscase, the device profile DB 306 may be formed as shown in table 2. Intable 2, it is noted that the old IP address corresponding to theanalysis requested IP address 121.516.6541 is null.

TABLE 2 Old IP address Current IP address null 121.516.6541 111.181.2201221.321.6542 132.213.8465 135.321.6557 — —

The context analyzer 302 records the source IP address of thecorresponding packet as the IP address of the device 300 and, afterward,stores and analyzes the context based on the packetstransmitted/received with the corresponding IP address at step 322.

Meanwhile, if the first packet is transmitted from a server to thedevice 300 via the router 304 at step 314, the context analyzer 302detects this at step 310 (Option 2) and sends the device profile DB 306and IP request message for inquiry on whether the corresponding device300 has any IP address used previously at step 318.

If the device connects initially to receive the service, it has no oldIP address and thus the device profile DB 306 sends the device 300 an IPresponse message (Old IP Response) to notify that it is a new devicehaving no old IP address at step 320. Then the context analyzer 302records the destination IP address of the corresponding packet as the IPaddress of the device 300. Afterward, the context analyzer 302 storesand analyzes context using the packets transmitted/received with thecorresponding IP address at step 322.

FIG. 4 is a flow diagram illustrating the procedure for the contextanalyzer 402 to detect, when the IP address assigned to the device 400is changed, the change and associate the IP address with the previouslystored and analyzed user information.

In the state that the user information is collected and analyzedaccording to the procedure depicted in FIG. 3, the IP address assignedto the device may be changed at step 408.

If the first packet is transmitted by the device 400 at step 412 afterthe change of the IP address of the device, the context analyzer 402detects the appearance of a new IP address at step 410 (Option 1). Thanthe context analyzer 402 sends the device profile DB 406 an IP requestmessage (Old IP Request) for inquiry on whether the corresponding device400 has any IP address assigned previously at step 416 (Option 1). Atthis time, the context analyzer 402 sends the IP request message (Old IPRequest) including the source IP address at step 418.

Then the device profile DB 406 search the DB for the old IP addressassigned to the device 400 which uses the corresponding IP address. Thedevice profile DB 406 sends the context analyzer 402 the IP responsemessage (Old IP Response) including the old IP address information atstep 420. In this embodiment, the device profile DB 406 may be formed asshown in table 3.

TABLE 3 Old IP address Current IP address 125.544.8765 121.516.6541111.181.2201 111.181.2201 132.213.8465 132.213.8465 — —

Referring to table 3, suppose that the device using the old IP addressis assigned a new IP address 121.516.6541. Then the context analyzer 402requests the device profile DB 406 for the old IP address device whichhas used the IP address 121.516.6541. Then the device profile DB 406checks the old IP address 125.544.8765 of the device using the IPaddress 121.516.6541. The device profile DB 406 sends the contextanalyzer 402 the retrieved IP address 125.544.8765. Then the contextanalyzer 402 is capable of checking the context occurring with the newIP address is associated with the device using the old IP address basedon the old IP address received from the device profile DB.

Accordingly, the context analyzer 402 accumulates the new context ontothe old context at step 424. That is, the old IP address is updated tothe new IP address, and the context managed with the old IP address ischanged to the context associated with the new IP address.

Detailed description is made thereof with reference to tables 4 and 5.

Table 4 is an exemplary user context management table retained by thecontext analyzer 402 before IP address update.

TABLE 4 IP address Context 125.544.8765 a1, a2, a3, 111.181.2201 b1, b2,b3, 132.213.8465 c1, c2, c3, — —

If the context analyzer 420 checks the IP address update from125.544.8765 to 121.516.6541 as a result of the inquiry to the deviceprofile DB 406, it updates table 4 to table 5.

TABLE 5 IP address Context 125.544.8765 −> 121.516.6541(update) a1, a2,a3, a4, a5, 111.181.2201 b1, b2, b3, 132.213.8465 c1, c2, c3, — —

That is, the context analyzer 403 updates the IP address to a new oneand updates the information a4 and a5 generated with the correspondingIP address to the context associated with the IP address 121.516.6541.

As described above, according to an embodiment of the present invention,the context analyzer 402 or the device profile DB stores and updatesonly IP addresses but not any information capable of identifying thereal device or user. Accordingly, it is possible to provide the contextaware service without invading user privacy.

After the IP address of the device 400 has changed, it may occur thatthe first packet is transmitted from a server to the device via therouter 404. In this case, the context analyzer 402 detects theappearance of a new IP address at step 410 (Option 2) and sends thedevice profile DP 406 an IP request message (Old IP Request) to inquirewhether there is any IP address assigned previously to the device 400 atstep 416 (Option 1). For this purpose, the context analyzer 402transmits the IP request message including the destination IP address atstep 418. Then the device profile DB 406 search for the old IP addressassigned to the device 400 using the corresponding IP address. Thedevice profile DB 406 sends the context analyzer 402 the IP responsemessage (Old IP Response) to notify of the old IP address of the device400 at step 420.

Another embodiment of the present invention is described brieflyhereinafter with reference to FIG. 4. FIG. 4 is directed to a method forthe context analyzer 402, when the IP address of the device 400 ischanged in the state of collecting and analyzing the user information atstep 408, to detect the change and acquire the old IP address from thedevice profile DB 406.

According to another embodiment of the present invention, the deviceprofile DB 406 may notifies the context analyzer 402 that the device 400has used a specific IP address is assigned a new IP address at step 422.In this case, the context analyzer 402 is capable of checking that theuser context generated with the new IP address is associated with thedevice which has used the old IP address based on the old address so asto accumulate the new context onto the old context at step 424.

In the method according to the another embodiment of the presentinvention, the context analyzer 402 or the device profile DB stores andupdates only the IP address without storing or using any informationcapable of identifying the real device or user. Accordingly, it ispossible to provide the context aware service without invasion of userprivacy. A description is made of the device alias-based contextcollection and analysis method according to another embodiment of thepresent invention.

FIG. 5 is a flow diagram illustrating the procedure of collecting andanalyzing context based on the device alias.

Since the operation of detecting, at the context analyzer 502, thepacket transmitted to or received from the device with a new IP addressis identical with that of the above embodiment, detailed descriptionthereon is omitted herein.

If a new IP address is detected, the context analyzer 502 sends thedevice profile DB 506 a device alias request message at step 518 toinquire the alias of the device using the corresponding IP address.

Then the device profile DB 506 searches for the device assigned thecorresponding IP address to check the alias of the device. In thisembodiment, the device profile DB 506 is exemplified as shown in table6. In table 6, the IP address is updated immediately when new IP addressis assigned to the device.

TABLE 6 Device (Alias) IP address Apple 121.516.6541 Bus 221.321.6542mountain 135.321.6557 — —

If the IP address inquired by the context analyzer 502 is 221.321,6542,the device profile DB 506 notifies that the inquired IP address isassigned to the device alias ‘bus’ at step 520.

At this time, since any information capable of identifying the device isnot stored or used in the system, the use of device alias isadvantageous in privacy protection.

If the device alias received from the device profile DB 506 is a newone, the context analyzer 502 maps the device alias and thecorresponding IP address and collects and analyzes the user context onthe transmitted/received packets.

If the context analyzer 502 has the user context associated with thedevice alias already, the context analyzer 502 maps the device alias tothe new IP address to continue collecting and analyzing the user contextwith the transmission/reception packets.

In this case, the user context management table retained by the contextanalyzer 502 is exemplified as shown in table 7.

TABLE 7 Device (Alias) Context Apple a1, a2, a3, Bus b1, b2, b3,mountain c1, c2, c3, — —

For example, it is assumed that the context analyzer 502 receives aresponse including an IP address 211.321.6542 mapped to the device alias‘bus’. Then the context analyzer 502 updates the context collected withthe IP address to the context in match with the device alias ‘bus’ asshown in table 7.

FIG. 6 is a flowchart illustrating the context management procedure ofthe context analyzer according to an embodiment of the presentinvention.

FIG. 6 shows the flow according to the representative embodiment of thepresent invention, and the flows according to other embodiment areclarified by referencing FIG. 6.

First, the context analyzer detects the packet transmitted by a certaindevice at step S610. The context analyzer requests the device profile DBfor the information on the IP address of the device transmitting thepacket at step S620. The information on the IP address denotes the IPaddress used by the same device before the assignment of the current IPaddress.

The context analyzer determines whether a response is received from thedevice profile DB at step S630. If no response is received, the contextanalyzer waits for the response transmitted by the device profile DB atstep S640.

If the response is received, the context analyzer determines where theresponse includes the old IP address information used by the same deviceat step S650. If no old IP address information is included, the contextanalyzer records the source IP address of the detected packet at stepS660. Otherwise if the old IP address information is included, thecontext analyzer updates the old IP address of the corresponding deviceto the new IP address.

The context analyzer stores and analyzes the user context informationassociated with the newly recorded device IP at step S670.

FIG. 7 is a block diagram illustrating a configuration of the contextanalyzer according to an embodiment of the present invention. As shownin FIG. 7, the context analyzer may include an interface unit 710, astorage unit 720, and a control unit 730.

The interface unit 710 is provided with a communication mean withnetwork nodes according to an embodiment of the present invention.Particularly, the interface unit 710 of the present invention mayinclude wired/wireless interface for detecting the packet transmittedfrom a wired or wireless terminal to the network and an interface withthe device profile DB for requesting for the IP address information andreceiving the response.

The storage unit is responsible for storing the program and dataassociated with the operation of the context analyzer. Particularly inan embodiment of the present invention, the storage unit 720 may includea user context storage region 721.

The user context storage region 721 may store the user contextmanagement table as exemplified in table 4. The user context managementtable includes an IP address field and a context field. The IP addressis used as an identifier for identifying a certain device and updatedcontinuously through communication between the context analyzer and thedevice profile DB. The context includes user information, and the usercontext may denote the information including at least one of purchasehistory, user location, preference, click history, Social NetworkService (SNS) information.

The control unit controls overall operations of the context analyzeraccording to an embodiment of the present invention and signal flowsamong the blocks. According to an embodiment of the present invention,the control unit 730 may further include a context manager 731.

The context manager 731 may detect packets transmitted/received betweendevice and server through wired or wireless link. The context manager731 sends the device profile DB an IP request message to request for theinformation on the IP address of the device. The context manager 731receives an IP response message transmitted by the device profile DB andcontrols updating the context based on the IP address informationincluded in the IP response message.

In this case, the IP address information may denote the IP address usedbefore the assignment of the current IP or the alias of the device usingthe currently assigned IP address.

If the device connects to the system initially, the IP response messagedoes not include the information on the old IP address used previously.Otherwise if it is not the first connection to the system, the IPresponse message includes the information on the old IP address usedpreviously. In this case, the context manager 731 controls such that theold IP address included in the context to be updated to the currentlyassigned IP address.

Although the description is directed to the case share the contextmanager 731 is implemented as a separate block and the blocks areresponsible for different functions, this is only for the conveniencepurpose but the functions are not differentiated among each other. Forexample, a certain function of the context manager 731 may be executedby the control unit 730 in itself.

What is claimed is:
 1. A method in a communication system, the methodcomprising: detecting data transmitted between a device, to which a newtemporary identifier is assigned, and a first server; receiving, from asecond server, information on a previous temporary identifier of thedevice based on the new temporary identifier of the device; and managinga user context of the device by mapping the previous temporaryidentifier of the device and the new temporary identifier of the device.2. The method of claim 1, wherein the previous temporary identifierinformation comprises information for a previous IP address or aprevious alias used by the device before a new IP address or a new aliasis assigned.
 3. The method of claim 2, wherein the managing of the usercontext comprises updating the previous IP address or the previous aliasof the device to the new IP address or the new alias assigned currentlyfor the device.
 4. The method of claim 1, wherein the user contextincludes at least one of user activity information and user serviceusage information those comprise at least one of purchase history, userlocation, preference, click history, and social network server (SNS)information.
 5. The method of claim 1, wherein the user context of thedevice is managed without a user identification of the device.
 6. Anapparatus in a communication system, the apparatus comprising: atransceiver; a storage unit for storing a user context; and at least oneprocessor configured to: detect, via the transceiver, data transmittedbetween a device, to which a new temporary identifier is assigned, and afirst server; receive, via the transceiver, from a second server,information on a previous temporary identifier of the device based onthe new temporary identifier of the device; and manage the user contextof the device by mapping the previous temporary identifier of the deviceand the new temporary identifier of the device.
 7. The apparatus ofclaim 6, wherein the previous temporary identifier information comprisesinformation for a previous IP address or a previous alias used by thedevice before a new IP address or a new alias is assigned.
 8. Theapparatus of claim 7, wherein the at least one processor is furtherconfigured to update the previous IP address or the previous alias ofthe device to the new IP address or the new alias assigned currently forthe device.
 9. The apparatus of claim 6, wherein the user contextincludes at least one of user activity information and user serviceusage information those comprise at least one of purchase history, userlocation, preference, click history, and social network server (SNS)information.
 10. The apparatus of claim 6, wherein the at least oneprocessor is further configured to manage the user context of the devicewithout a user identification of the device.
 11. A method in acommunication system, the method comprising: receiving, from a firstserver, a request for information on a previous temporary identifier ofa device, the device to which a new temporary identifier is assigned,based on the new temporary identifier of the device; and transmitting,to the first server, a message including the information on the previoustemporary identifier of the device, wherein a user context of the deviceis managed by mapping the previous temporary identifier of the deviceand the new temporary identifier of the device.
 12. The method of claim11, wherein the previous temporary identifier information comprisesinformation for a previous IP address or a previous alias used by thedevice before a new IP address or a new alias is assigned.
 13. Themethod of claim 12, wherein the previous IP address or the previousalias of the device is updated to the new IP address or the new aliasassigned currently for the device.
 14. The method of claim 11, whereinthe user context includes at least one of user activity information anduser service usage information those comprise at least one of purchasehistory, user location, preference, click history, and social networkserver (SNS) information.
 15. The method of claim 11, wherein the usercontext of the device is managed without a user identification of thedevice.
 16. An apparatus in a communication system, the apparatuscomprising: a transceiver; a storage unit for storing a previoustemporary identifier and a new temporary identifier of a device; and atleast one processor configured to: receive, via the transceiver, from afirst server, a request for information on the previous temporaryidentifier of the device, the device to which the new temporaryidentifier is assigned, based on the new temporary identifier of thedevice; and transmit, via the transceiver, to the first server, amessage including the information on the previous temporary identifierof the device, wherein a user context of the device is managed bymapping the previous temporary identifier of the device and the newtemporary identifier of the device.
 17. The apparatus of claim 16,wherein the previous temporary identifier information comprisesinformation for a previous IP address or a previous alias used by thedevice before a new IP address or a new alias is assigned.
 18. Theapparatus of claim 17, wherein the at least one processor is furtherconfigured to update the previous IP address or the previous alias ofthe device to the new IP address or the new alias assigned currently forthe device.
 19. The apparatus of claim 16, wherein the user contextincludes at least one of user activity information and user serviceusage information those comprise at least one of purchase history, userlocation, preference, click history, and social network server (SNS)information.
 20. The apparatus of claim 16, wherein the user context ofthe device is managed without a user identification of the device.